Synthesis and Characterisation of Extended pi-Bonding Systems in Cycloimmonium Ylides Derived From the 4,4'-Bipyridine

摘要

Disubstituted cycloimmonium ylides derived from the 4,4'-bipyridine with one, two or four ylidic systems in their molecular structure are described as stable compounds. Synthesis of some bridged 1,1'-disubstituted 4,4'-bipyridinium dimethylides in which 1,4-or 1,3-phenylene spaces may be used, provide some new macromolecular cycloimmonium ylides with spatially extended pi-bonding system. These compounds were obtained by the chemical conversion of 4,4'-bipyridinium salts as viologens or bis-viologens, with acylating or carbamoylating agents, in basic media. The characterisation of all compounds has been mainly performed by ~1H and ~13C NMR spectroscopy.